It is obvious that over many years the slang has been interpreted in many ways by different people and it is still happening today.
Just because you were with people talking it long before minder does not mean it is wrong. Minder is a good example to quote from as it is full of slang and I am...
Slaughter is house as in slaughter house I think, but a home is also a drum but I know not why. This is still all from Minder.
Jacobs is one of my favourites, Jacobs crackers , knackers
How much does a Cockney spend on shampoo?
Paaaan ten
The reason I think it is a watch is because the word kettle was used in quite a few episodes of Minder when Arfur Daley was flogging dodgy watches to Dave behind the bar at the Winchester Club.
Unless the resesrchers at Thames TV/Euston Films got it wrong.
But as in piles cockney slang is open...